Process of preparing frozen fruit or vegetables

Abstract

To reduce the quantity of waste waters which must be treated in sewage farms most of the waste water which is produced in blanching and cooling stages, is eliminated. The present process comprises treating fruit or vegetables in the conventional manner up until the blanching stage, blanching them in steam and recovering a condensate, cooling them in air and preferably spraying with water or with some of the condensate, or following the air-cooling with a passage in cold water in a cooling cycle. After adding the required quantity of salt to the vegetables for example, they are frozen and their surfaces are glazed with all or some of the condensate. This process also increases the yield the prevents the loss of valuable soluble substances.

We claim: 
     
       1. A process for the preparation of frozen fruit or vegetables, in which the volume of waste waters is reduced, comprising blanching the fruit or vegetables in an atmosphere containing steam, recovering condensate produced during said blanching, cooling the blanched fruit or vegetables in an essentially gaseous medium, freezing the cooled fruit or vegetables and glazing the frozen fruit or vegetables by contacting the frozen fruit or vegetables with at least some of the condensate produced during blanching. 
     
     
       2. A process according to claim 1 wherein coarse particles are removed from the condensate, at least some of the condensate is concentrated and the concentrated condensate is used for glazing the frozen fruit or vegetables. 
     
     
       3. A process according to claim 2 wherein some of the condensate is sprayed over the product during the cooling stage. 
     
     
       4. A process according to claim 2 wherein all of the condensate is concentrated to the exact volume required for glazing. 
     
     
       5. A process according to claim 2 wherein the condensate which has been freed from coarse particles is treated with ion-exchange resin in order to remove undesirable soluble substances. 
     
     
       6. A process according to claim 1 further comprising transferring the cooled fruit or vegetables into an aqueous medium, further cooling the fruit or vegetables in the aqueous medium, and recycling the aqueous medium through a heat-exchanger. 
     
     
       7. A process according to claim 1 further comprising spraying onto the fruits or vegetables during the cooling step an aqueous medium, and further recycling the aqueous medium through a heat-exchanger. 
     
     
       8. A process according to one of claims 1 to 7 for the treatment of vegetables wherein after the vegetables have been cooled, the salt content thereof is adjusted by passing the cooled vegetables into a brine, separating the cooled vegetables from the brine, recycling the brine, washing the vegetables and recycling the washing water through a heat-exchanger.